Examine source code of Quick Age Calculator

{
  "manifest_version": 2,
  "name": "__MSG_extensionName__",
  "version": "1.0.0",
  "description": "__MSG_extensionDescription__",
  "default_locale": "en",
  "browser_specific_settings": {
    "gecko": {
      "id": "{15db23b6-8c7c-48e6-a48d-d27059944c52}",
      "strict_min_version": "93.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "permissions": [],
  "browser_action": {
    "default_icon": {
      "16": "assets/icons/icon16.png",
      "32": "assets/icons/icon32.png",
      "48": "assets/icons/icon48.png",
      "96": "assets/icons/icon96.png"
    },
    "default_title": "__MSG_extensionName__",
    "default_popup": "src/popup.html"
  },
  "icons": {
    "16": "assets/icons/icon16.png",
    "32": "assets/icons/icon32.png",
    "48": "assets/icons/icon48.png",
    "96": "assets/icons/icon96.png"
  }
}